[PLUG] Find Open Ports

[Casey Bralla <MailList@nerdworld.org>]

My employer is very aggressive in closing off ports.  This makes it hard for me 
to access my home network from work.  Luckily, port 23 is open so I can ssh 
in, and of course, port 80 is left alone.

However, I've got several special web pages that run on computers behind my 
firewall.  I access them through port forwarding to non-standard ports (such as 
81 & 82).

Unfortunately, since my employer blocks these ports, I can't use them.   I do 
have unlimited discretion, however, in assigning my programs to whatever port 
I desire.

So....  if I knew which ports were NOT blocked, I could use those.

BUT...  How do I check to see if what ports are available?

So far, I've been able to come up with 2 ideas:  1) scan every port, and 2) 
try ports manually one at a time.



I could run a portscan on my portable, but that would undoubtedly raise all 
kinds of alarms.  Also, I'd have to be sure I was connecting to something that 
had those ports active.


Does anybody have any suggestions on how to test to see if a series of ports 
is not filtered, or have a suggestion of ports that I could test manually 
through trial and error?
-- 

Casey Bralla
Chief Nerd in Residence
The NerdWorld Organisation

http://www.NerdWorld.org
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